Cita APA (7th ed.)

Gilbert, J. B. (1993). Clear speech: Student book (2ª ed.). Cambridge University Press.

Cita Chicago (17th ed.)

Gilbert, Judy B. Clear Speech: Student Book. 2ª ed. United Kingdom: Cambridge University Press, 1993.

Cita MLA (9th ed.)

Gilbert, Judy B. Clear Speech: Student Book. 2ª ed. Cambridge University Press, 1993.